ORT Series Rotary Table Bearings — Precision and Versatility for Advanced Machinery

The rotary table bearing is fundamental to CNC performance, and our ORT series represents a comprehensive solution for demanding applications across multiple industries.

Understanding the ORT series

The ORT rotary table bearing integrates two thrust roller bearings and one radial cylindrical roller bearing into a single, pre-assembled unit. This thrust/radial combination allows the bearing to support radial forces, axial forces from both directions, and tilting moments—all free from clearance. The bearings come fully greased and ready to install, providing high rigidity, high load capacity, and particularly high accuracy upon first operation.

ORT series breakdown

ORT standard rotary table bearings provide general-purpose high-precision capability. They are the most suitable choice for applications with low speeds and short operating durations, such as indexing tables and swivel-type milling heads.

ORTS high-speed rotary table bearings achieve higher speed limits through internal structural optimization while maintaining the same external dimensions as the standard series—enabling direct replacement without redesign. The YRTS variant (equivalent to ORTS) features a specially designed internal geometry that significantly improves permissible speed limits over the YRT standard series.

ORTM rotary table bearings with integrated measuring system combine an angle measurement system with the base ORT assembly. This combined bearing delivers measurement accuracy up to 1 arc second while simultaneously withstanding axial loads, radial loads, and overturning moments—ideal for high-precision CNC rotary tables, dividing heads, and research measurement applications.

OKLDF bidirectional thrust angular contact ball bearings handle precise bidirectional axial loading with high stiffness characteristics.

Technical specifications and available sizes

ORT series bearings are available across a wide range of sizes, including YRT50 (50 mm bore, 126 mm OD, 30 mm height), YRT120 (120 mm bore, 210 mm OD, 40 mm height), YRT200 (200 mm bore, 300 mm OD, 45 mm height), YRT395 (395 mm bore, 525 mm OD, 65 mm height), YRT650 (650 mm bore, 870 mm OD, 122 mm height), and up to YRT1200 (1,200 mm bore, 1,490 mm OD).

Key performance advantages

When paired appropriately, ORT bearings deliver exceptional tilted rigidity and high precision. They support radial loads and axial loads from both sides, eliminating axial clearance after preloaded fits. With integrated screw mounting holes on both housing and shaft washers, ORT bearings simplify assembly while ensuring secure attachment under dynamic loading.

Applications across industries

• Five-axis machining centers : Rotary axes requiring high rigidity under high-speed cutting

• Indexing tables and dividing heads : Low-speed positioning with small operating durations

• Precision measuring equipment : Research measurement requiring 1-arc-second angular accuracy

• Medical imaging systems : Rotating gantries demanding micron-level radial runout control

• Industrial robot bases and waist joints : Support platforms handling combined loading profiles

Ouna’s ORT series offering

At Luoyang Ouna Bearing, we manufacture the complete ORT series—standard, high-speed, and measuring system variants—plus the OKLDF bidirectional thrust bearings. All units achieve P5, P4, and P2 precision grades with outer diameters from φ20mm to φ2500mm. Each ORT bearing is pre-greased, pre-adjusted for clearance-free operation, and ready for immediate installation upon delivery.

Need a rotary table bearing solution? Contact us for application-specific ORT selection support or request our ORT technical guide covering series selection, mounting recommendations, and performance data for your particular machine tool or precision equipment application.